Amchepry (Raguneprocel) by Sumitomo Pharma: status and timeline

Amchepry (Raguneprocel)

Replace lost dopamine-producing neurons in the brain to improve motor symptoms in Parkinson's disease patients, offering a potential cure rather than symptomatic management.

DeployStage 4 of 5

Conditional approval (Japan, March 2026); full approval in seven years with additional data.

Updated 6 Mar 2026Checked 11 Oct0 updates this week

Milestones

Next · Full approval data collection and submission

Phase I/II trial enrollment at Kyoto UniversityQ1 2022Complete.
24-month safety and efficacy data completed2025Complete.
Japanese regulatory recommendation for approvalFeb 2026Complete.
Conditional approval granted by MHLW6 Mar 2026Complete.
Full approval data collection and submissionTarget 2033Not yet reached.

Most important updates

Upcoming

2033Full approval data collection and submission (next)

Current obstacles

Immune rejectionAllogeneic donor cells may trigger immune response; long-term tolerance strategies are under investigation.
Surgical complexityBrain implantation requires stereotactic neurosurgery, limiting accessibility and requiring specialized centres and training.
Cell engraftment variabilitySuccess depends on consistent cell survival, integration, and dopamine production, which may vary between patients.

Physics limits

Cell transplant volumeThe brain region (putamen) has finite volume; total cell volume that can be safely implanted is limited, constraining the mass of dopamine-producing tissue.
Neuronal integrationTransplanted neurons must form functional synaptic connections with host brain circuits; this integration process is not fully controllable and varies with individual neurobiology.
Disease progressionParkinson's involves progressive loss of dopamine neurons throughout the brain, not only in the putamen; localized transplantation does not address broader neurodegeneration.

How it works

3 parts

Donor cells

iPSCs from blood

Donor blood cells are reprogrammed to induced pluripotent stem cells, which can become any cell type in the body.

Differentiation

Become dopamine neurons

Through controlled culturing, the iPSCs differentiate into dopaminergic neural progenitor cells that will produce dopamine.

Transplantation

Direct brain implant

Cell aggregates are surgically implanted into the putamen, a brain region that controls movement, to replace neurons lost to Parkinson's.

Spec sheet

Spec	Amchepry (Raguneprocel)
Low cell dose per hemisphere	5 million cells^R (reported)
High cell dose per hemisphere	10 million cells^R (reported)
Phase I/II trial follow-up	24 months^R (reported)
Trial enrollment	Seven patients^R (reported)
Motor benefit off medication	4 of 6^R (reported)

^R reported by the company

Update log

2 updates

Fri 6 Mar

Major: Sumitomo Pharma's Amchepry receives formal approval from Japan's Ministry of Health, Labour and WelfarePressRegulatory

Tue 24 Feb

Major: Japanese regulatory panel recommends approval of Amchepry, world's first iPSC-derived therapyPressRegulatory

About Sumitomo Pharma

The team behind Amchepry (Raguneprocel)

Sumitomo Pharma

Amchepry, iPSC dopaminergic cells, Parkinson's

Japanese pharmaceutical company developing cell therapies. Developed Amchepry, the world's first approved iPSC-derived regenerative medicine (Japan, 2026). Founded 2005 through merger; headquartered in Osaka.

Amchepry: world's first approved iPSC-derived therapy (Japan, March 2026) for Parkinson's disease.
Dopaminergic neural progenitor cells from donor iPSCs transplanted to the brain putamen.
Phase I/II: seven patients (24 months); 4/6 improved without medication, 5/6 with medication.

sumitomo-pharma.com (opens sumitomo-pharma.com)Company profile →

Founded: 200521 yrs
Headquarters: Japan
Status: Public
Listed: 4506 (opens google.com)TSE
Valuation: public
Works in: BiotechCell & organ therapies
Coverage: 1 program · 2 updateslatest 6 Mar 2026checked 11 Oct
Partners: Racthera (opens sumitomo-pharma.com)

Spec

Amchepry (Raguneprocel)

Low cell dose per hemisphere

5 million cells^R (reported)

High cell dose per hemisphere

10 million cells^R (reported)

Phase I/II trial follow-up

24 months^R (reported)

Trial enrollment

Seven patients^R (reported)

Motor benefit off medication

4 of 6^R (reported)